This is a fantastic general beauty tip as it's meant to prevent wrinkles too. Silk pillow cases!! A must for curly peeps. While fine Egyptian cotton might feel soft to touch. It's texture may still cause frizz. Silk on the other hand definitely won't. Also it keeps you cool when your hot and warm when your cold. Perfect!! Go on, your curls deserve it.
Here's a quick link to help with what we're telling you: http://www.johnlewis.com/search/silk-pillowcases?_requestid=792577